Electrical contact

ABSTRACT

A free-standing, guided entry metallic one-piece female spring contact is provided which has particular utility in conjunction with integrated circuits. The contact is intended to be mounted, together with a multiplicity of similar contacts, in plated holes in a printed circuit board. The contact is formed to define two opposing spring leaves which receive the pins or tab-like male contacts, for example, of an integrated circuit device. The contact also defines an integral apertured crown over the spring leaves which serves as a guide for the male contact.

United States Patent 1191 11 1 3,824,557

Mallon July 16, 1974 ELECTRICAL CONTACT 3,733,574 5/1973 Scoville et al339/17 c [75] Inventor: Marvin C. Mallon, Canoga Park, FOREIGN PATENTSOR APPLICATIONS Callf- 2,036,990 11/1971 Germany 339/253 R 73 AssigneeZInterdyne p y, v Nuys, 54,552 lO/l949 France 339/258 R Calif.

, Primary Examiner-Henry C. Sutherland [22] Flledi' July 1973 AssistantExaminerWilliam F. Pate, Ill [2 App], 379 105 Attorney, Agent, orFirm-William W. Haefliger Related [1.8. Application Data [57] ABSTRACT Afree-standing, guided entry metallic one-piece female spring contact isprovided which has particular 3 Claims, 1 Drawing Figure 7 1 ELECTRICALCONTACT BACKGROUND OF THE INVENTION Integrated circuits are being usedin increasing numbers in electronic equipment. Integrated circuitsusually take the form of a block in which the integrated electroniccircuitry and active electronic elements are located, and contactsprotruding outwardly from the block. These contacts usually havea pin ortab-like configuration. V As mentioned above, the contacts of thepresent" invention may be conveniently mounted in plated holes in thecircuit board on which the integrated circuit is to be mounted, and thecontacts constructed in accordance with the invention provide femaleconnectors for the male contacts from the integrated circuit. Thecontacts not only establish electrical connection between the integratedcircuit and the external circuitry of the circuit board, but they alsoserve as a means for supporting and mounting the integrated circuit onthe circuit board.

A feature of the contact of the invention, as previously pointed out, isthe provision of a guide for each Contact. This guide serves to directthe entry of the male contacts of the integrated circuit block betweenthe corresponding spring leaves of the Contact, and into electricalengagement with the contact. v

The'construction of the Contact of the present invention, as will bedescribed, is such that the contact may be installed economically in acircuit board using semiautomatic insertion equipment. When thecontactis installed, its contour provides a gas-tight, reliable solderlessjoint to the printed circuit board. The spring leaves formed by theContact of the invention provide a lowresistance, high-pressureengagement with the integrated circuit contact. Moreover, theguided-entry element of the contact of the invention safeguards thecontact and assures the most reliable interface between the integratedcircuit and the contact.

DRAWING DESCRIPTION as received in a plated hole in a usual printedcircuit board.

DETAILED DESCRIPTION As shown in the drawing, the contact constructed inaccordance with the invention is received in a plated hole 10 in aprinted circuit board 12. It will be understood that a multiplicity ofsimilar contacts may be so received, and arranged in parallel rows, soas to receive the pin-like or tab-like contacts of an associatedintegrated circuit module. The contact itself, as shown in the drawing,is designated generally as 14, and it comprises an integral socketportion 16, and a shank portion 18, having a one piece, integral,off-set construction.

The shank 18 of the contact in the illustrated embodiment is square incross-section and designed for' wire-wrap applications. At a pointdirectly above the square shank 18, a tapered section 20 acts as a wedgewhen the contact is inserted in the plated hole 10 in the 2 printedcircuit board 12. A gas-tight reliable joint is thereby formed at theinterface of the four corners of the wedge-shaped portion 25 of thecontact and the electrically conductive bore of the hole 10. In thisway, a gas-tight, reliable, solderless connection is made between thecontact 14 and the Circuitry on the printed circuit board 12.

Directly above the wedge-shaped portion 20, the contact 14 is formedinto a pair of opposing strips 22 and 24, these strips being folded backon themselves,

as shown in the drawing, to form two opposing spring leaves. The leavesreceive the pin-like or tab-like Contact of the integrated circuit, orother module, which makes intimate electrical engagement with the twoleaves 22 and 24, and which isfirmly supported between the leaves.

A further strip-like portion 26 is formed integral with the shank 18adjacent to the wedge-like portion 20, the latter strip-like portion ofthe contact extending up adjacent to the leaves 22 and 24, and having abent-over crown section'extending over the top of the leaves. The crownsection has an opening which, in the illustrated embodiment isrectangular and indented as shown. The indentations serve to furtherguide the male tab of the integrated circuit module. This opening alsoserves as a rigid support for the Contact thereby preventing abuse ofthe spring leaves 22 and 24 below the contact, and insuring a wellcentered interface between the integrated circuit module and the contactThe contact 14 may be composed of beryllium copper, or other appropriateresilient electrically conductive material. Y

The invention provides, therefore, an improved onepiece guided entryfree-standing electrical contact which serves as an improved andpositive electrical connector for an integrated circuit module, or thelike. The contact of the invention not only is relatively simple andinexpensive to construct, but also may be inserted easily and bysemi-automatic insertion machines into the printed circuit boards.

It will be appreciated that although a particular embodiment of theinvention has been shown and described, modifications may be made. It isintended in the following claims to cover such embodiments as fallwithin the spirit and scope of the invention.

I claim:

1. An electrical contact adapted to be supported on a circuit boardhaving a bore, comprising a. an upright, elongated shank having mainextent freely receivable through said bore to project at one side ofsaid board, said shank main extent having a main polygonal cross sectionto define corners for engagement with the turns of a wire wrap- P 8 b.the shank also having a relatively short portion above said main extent,said short portion having a polygonal cross section larger than thecrosssection of the shank main extent and defining corners spaced apartto tightly engage said bore when said short portion extends therein,there being at least two downwardly tapering walls on the shank formerging said short portion thereof with said main extent,

c. an L-shaped flat metallic strip having an elongated portion extendingupwardly from the shank and a laterally forwardly extending crownportion defining a central guide opening, and

d. a pair of like, V-shaped flat metallic spring strips through thecrown at the opposite side of said each having an outer leg extendingupward y board and into position between said free ends.

toward the crown Pomon and an Inner g extend 2. The contact of claim 1and including said circuit s downwardly y from the ciown PQ and boarddefining said bore engaged by said corners of the Sald legs mergmg at asharp fold m relanvely close 5 shank short portion, said outer leg lowerextensions proximity to siilld F saidlegs.having having lower edgeslocated adjacent said board. rearwardly projecting lower extensionsJoined to 3. The contact of claim 1 wherein said central guide saidelongated portion of the L-shaped strip near a Said Short portion of theshank and Said inner egg open of the crown has rectangularconfiguration, the

tapering downwardly and toward one another crown top surface extentbounding said opening tapertween said outer legs to define closelyspaced free mg downwflrdly gulde 531d P Inserted dflwnwardly endslocated closer to said extensions than to said roug Said opening.

crown for contacting a pin guidably inserted

1. An electrical contact adapted to be supported on a circuit boardhaving a bore, comprising a. an upright, elongated shank having mainextent freely receivable through said bore to project at one side ofsaid board, said shank main extent having a main polygonal cross sectionto define corners for engagement with the turns of a wire wrapping, b.the shank also having a relatively short portion above said main extent,said short portion having a polygonal cross section larger than thecross section of the shank main extent and defining corners spaced apartto tightly engage said bore when said short portion extends therein,there being at least two downwardly tapering walls on the shank formerging said short portion thereof with said main extent, c. an L-shapedflat metallic strip having an elongated portion extending upwardly fromthe shank and a laterally forwardly extending crown portion defining acentral guide opening, and d. a pair of like, V-shaped flat metallicspring strips each having an outer leg extending upwardly toward thecrown portion and an inner leg extending downwardly away from the crownportion, and said legs merging at a sharp fold in relatively closeproximity to said crown, said outer legs having rearwardly projectinglower extensions joined to said elongated portion of the L-shaped stripnear said short portion of the shank, and Said inner legs taperingdownwardly and toward one another between said outer legs to defineclosely spaced free ends located closer to said extensions than to saidcrown for contacting a pin guidably inserted through the crown at theopposite side of said board and into position between said free ends. 2.The contact of claim 1 and including said circuit board defining saidbore engaged by said corners of the shank short portion, said outer leglower extensions having lower edges located adjacent said board.
 3. Thecontact of claim 1 wherein said central guide open of the crown hasrectangular configuration, the crown top surface extent bounding saidopening tapering downwardly to guide said pin inserted downwardlythrough said opening.